Russell FRAC-1 Installation Manual

MULTICON

Russell

INSTALLATION AND
MAINTENANCE
MANUAL

Bulletin No. 411.1
April, 1999

AIR COOLED FLUID COOLER

MODELS

FRAC-3/4 TO FRAC-3

FVAC-5 TO FVAC-216

US

Russell

221 S. Berry St. • Brea, CA 92821 • Tel [phone] • FAX [phone]

GENERAL UNIT LOCATION

Closed circuit fluid coolers are practical heat
rejection devices for use with relatively small capacity
packaged refrigeration systems used for process cooling
as well as specialized applications such as computer
rooms. During most of the year, it will deliver cooled fluid
temperatures approaching those obtained by a cooling
tower. The fluid cooler circulates the fluid inside a finned
tube coil specifically designed and circuited for the fluid
to be cooled.

One of the problems the fluid cooler has in
common with conventional cooling towers and evapora­tive cooled systems is operation in freezing climates.
This is overcome by the use of anti-freeze. The most
common anti-freeze is a 20% to 50 % so lu tion o f e thy l­ene or propylene glycol in water. The reduction in heat
transfer capability caused by use o f the an ti-fre eze is
partially compensated for by the use of higher coolant
flow rates. Even though additional energy is required to
pump the coolant, it results in lowering the co mpr essor
head pressure. Operating with this reduced pressure has
a greater effect on energy costs than doe s the highe r
water flow rate. Also, as there is no drift loss or evapora­tion in a closed coolant circuit. Anti-freeze must be
replaced only in the event of a leak.

As with any equipment, proper installation and
maintenance will improve performance and life
expectancy.

tall obstructions on three or more sides. See Figure 1
for minimum clearance from obstructions and between
units. Short circuiting of the air flow or the intake of
warmer air from another unit will seriously degra de the
performance of the fluid cooler. Noise consideration
should be considered when locating an flu id coo ler.
Proximity to windows, walls, and surrounding structures
can cause objections by the occupan ts. An acou stical
expert should be consulted when noise is of a particular
concern.

sufficiently strong to support the fluid cooler operating
weight. Consult with a professional structural engineer to
determine safe platform loading.

Do not locate any unit so as to be bordere d by

Structural supports and roof platforms should be

INSPECTION

Check all items against the bill of lading to make
sure all crates and cartons have been received. If there
is any damage, report it immediately to the carrier and
file a claim. Make sure the voltage on th e unit nameplate
agrees with the power supply available.

RIGGING AND HANDLING

FVAC 5 thru 19 model condensers are shipped
on their sides, and all other FRAC / FVAC models are
shipped flat. All units come shipped on a skid with a
wooden skeleton frame to prevent damage in transit.
Leave all framing attached until the unit is a s close as
possible to its final installed location.

All units have built in lifting lugs. Use spreader
bar(s) when necessary, failure to do so will damage the
air cooled condenser. Never use the coil headers or
return bends for moving or lifting the condenser.

INSTALLATION

1. Design structural supports to carry the weight of
the fluid cooler plus the fluid weight in the coil.

If this is a roof installation provide suitable flashing
of the roof. For ground level moun ting, a con cre te
pad is recommended. Mounting holes pe rmit the
unit to be bolted down to withstand wind pressure s.

2. The mounting legs of the fluid cooler are shipped in
a recessed position. Raise the unit to lower the
legs down and reinstall all fastener.

3. Level mounting is necessary to assure proper fluid
distribution through the coil as well as a flooded
suction for the pump.

4. Water piping must comply with local codes. Correct
pipe sizing will help reduce pu mping powe r and
operating costs.

5. If in doubt, consult Russell for the fluid cooler fluid
pressure drop at the spe cific cond ition s on your
job.

6. Provide sufficient valves and unions to permit easy
access to parts subject to wear and possible repair
or replacement.

7. After fluid piping is completed, all joints should be
leak tested.

8. Where city water make-up is required, follow local
plumbing codes and make certain that disconnecting
provisions are provided.

9. If the fluid cooler is supplied without starters, select
starters and wire in accordance with nameplate data
on the fan and pump motors. The installation must
conform to local codes.

PIPE INSTALLATION

The piping system should provide maximum leak
prevention. Weld or sweat joints should be used where
possible. If threaded pipe joints are used tightly drawn
teflon tape should be sufficient. A possibility that the
glycol solution or other heat transfer fluids will leak while
water will not, should be considered during installation.

A glycol system should not use a pressure
reducing valve. This is because a slight leak would lead
to dilution of the glycol mixture. Any refill should be con­trolled so as to maintain the proper glycol-to-water ratio.

Table 1 shows pressure drops for various pipe
sizes at flow rates commonly used with a typical fluid
cooler. These pipe sizes are standard connections act ual
size may vary according to available pump head. This
can be determined by subtracting from the total available
pump head at design flow, the cond ense r pressure drop
and the fluid cooler pressure drop. Allow some safety
factor for last minute pipe fittings added to the system
and for eventual fouling of the system.

(a) Glycol piping requires no insulation except
when fluid temperature will be below ambient dewpoint
temperatures. Fluid coolers normally produce about
70°F or higher fluid temperatures.

(b) Vents are required at all high points in piping
to bleed air when filling the system. If fluid coolers are at
high points, vent valves should be installed at each fluid
cooler.

(c) It is recommended that gate valves be
installed on both sides of the pump to prevent loss of
fluid in the event the pump should require repair or
replacement.

(d)

TABLE 1

Pressure Loss (Water) for a Typical Fluid Cooler

Schedule 40 Copper Tube
Flow Pipe Size Type L Steel Head Ft/100 Ft
GPM Steel O.D. Copper Head Ft/100 Ft Equiv. Laths.

15 1" 1-1/8" 27.8 15.0
20 1" 1-1/8" 50.8 23.1
24 - 1-1/8" - 32.3
24 1-1/4" 1-3/8" 25.8 12.7
30 1-1/4" 1-3/8" 40.6 18.5
32 1-1/4" 1-3/8" 42.5 20.8
40 - 1-3/8" - 30.0
40 1-1/2" 1-5/8" 27.8 12.9
45 1-1/2" 1-5/8" 37.0 16.4
60 - 1-5/8" - 27.7
60 2" 2-1/8" 14.9 7.6
80 2" 2-1/8" 27.8 12.0

TABLE 2

Pressure Drop Correction Factors:

Temperature

50% Glycol Solution vs Water

Fluid

°F

40 1.45 2.14
100 1.1 1.49
140 1.0 1.32
180 0.94 1.23
220 0.9 1.18

Pressure Drop

Correction @

Equal Flow

Total Pressure
Drop Correction;
50% Glycol Flow

(INcreased per Table 1)

FLUID CIRCULATING PUMP

Although Russell does not supply the circulation
pump, this section is general reference to pumps. Please
consult with the pump manufacturer for proper selection
and installation.

Mechanical seal type pumps mus t be used for
glycol systems. Gland type pumps will cause glycol
waste, and if used with a pressure reducing valve will
lead to dilution of the glycol mixture and eventual freeze­up.

Pump is selected for piping friction loss plus
pressure drop through the fluid cooler coil, plus pressure
drop through the heat source. No allowance for vertical
lift is made since in a closed system a counterhead acts
on the pump suction.

With glycol solution the pump performance curve
will drift to the right from its design point because differ­ences in circuit design: control valve application; pres­sure drop calculations; etc. The pump should be select­ed high on the curve so as to provide for the "drift". The
pump curve should be "flat" so that the pump will com­pensate for the inability to exactly predict the final oper­ating system flow condition and to provide sufficient flow
for satisfactory heat transfer and maximum protection
against freezing at the far end of the circuit. The pump
motor should have sufficient power for operation over the
entire pump curve, to prevent motor overload at reduced
voltages.